Catherine Shaw, 23, was last seen on Thursday.
The death of a British woman who went missing in Guatemala likely died in a "tragic accident", a missing persons charity has said.
Catherine Shaw had been staying in the Lake Atitlan area of the central American country.
It marked the second death of an immigrant child in detention after crossing the US-Mexico border this month.
An investigation has been ordered into whether emergency protocols were followed properly in the wake of the eruption.
The death toll rose to 99 on Wednesday, with nearly 200 still listed as missing.
More dramatic images have emerged showing the scale of destruction from the eruption of a deadly volcano in Guatemala.
At least 75 people died after the first eruption on Sunday.
The fast-moving flows overtook people in homes and streets with temperatures reaching as high as 700C.
A towering cloud of smoke has blanketed nearby villages in heavy ash.